In the past, roll type pattern attachments or yarn feed mechanisms have been extensively used with tufting machines for feeding the yarns to the needles of tufting machines according to prescribed patterns. Such a roll type yarn feed mechanism controls the rate at which prescribed yarns are fed to selected needles in the tufting zone of the tufting machine. This feed, in turn, controls the pile height, usually by causing the yarns to be robbed from the previously sewn loops in the backing material.
In the prior art it has usually been necessary, when a yarn breaks or when different yarns are to be tied to different needles, to re-wrap such yarn or yarns around a roller or rollers and re-thread the needles. Threading or rethreading of a tufting machine needle is quite laborious since usually each yarn must be wrapped around the roller or spindle, as the case may be, and threaded or rethreaded thereafter, each time there is to be a change of sequence of the yarns across the width of the machine.
The present invention enables intermediate portions of the yarns to be selected, after threading, and moved against and partially around any selected feed roller, thereby eliminating the necessity of wrapping the yarns around the roller or spindle and rethreading the needles, thereafter. This reduces materially the time required in making a change in sequence of yarns across the width of the tufting machine and eliminates the need for cutting each end of the yarn for the purpose of changing from one yarn feed axis (yarn feed roll) to another.